2, 2&#39;-(1, 4-diaminotetramethylene) bis(4-thiazolecarboxylic acid), salts and process



United States Patent Ofi ice 3,040,054 Patented June 19, 1962 Thisinvention relates to new chemical compounds and more particularly to anew thiazolecarboxylic acid of the formula 7 NH, NH;

j wll-hnomcmhn-w loofi H000 N I and salts thereof. Since thethiazolecarboxylic acid con- I tains both basic (i.e. amino) groups andcarboxylic acid groups it is amphoteric in nature and thus forms saltswith acids and bases. Although any acid or base may be used in preparingthe salts, the preferred acids are mineral acids, such as the hydrohalicacids (e.g.,.hydrochloric and hydrobromic acid), sulfuric acid, nitricacid and phosphoric acid. The preferred bases are ammonium hydroxide,alkali metal hydroxides (e.g., potassium hydroxide and sodium hydroxide)and alkaline earth metal hydroxides (e.g., calcium hydroxide). Inaddition organic acids, such as tartaric, citric and acetic acid, andorganic bases, such as alkylamines, can be used.

The new thiazolecarboxylic acid of this invention (as well as its salts)is useful as a precursor in the microbial preparation of the antibioticthiostrepton. For this purpose it is added at a concentration greaterthan about 0.001% (w./v.) to a nutrient medium containing a source ofcarbon and energy, a source of assimilable nitrogen and a source ofassimilable sulfur (such as that described in U.S. patent application,Serial No. 491,392, filed March 1, 1955 and now U.S. Patent No.2,982,689, granted May 2, 1961) when culturing Streptomyces azureus(Waksman Collection No. 3705, Institute of Microbiology, New Brunswick,New Jersey) for the production of thiostrepton.

The final products of this invention are prepared by a series ofreactions using as the initialreactant succinaldehyde. These reactionsare shown schematically by the following equations. In these equations,R is a hydrocarbon radical of less than ten carbon atoms, such aslowerKON BOOK 01' (RCO)2O CN CN A ROOOGHCHQCHZOHOOCR I B=phenyl O GHCH CH CHOn on s 1 s TOEF-CEzQHgCH-f Nacho, nooo ---N N 00011 r s 11 s jTiL-omorno noooNrn 1 1 l l 7 H000 N. N. 00011 7 H, NH; S I l S\ jTonemom-cnfl H000 N h VI i To prepare Compounds A, succinaldehyde isinteracted with a cyanide, such as an alkali metal cyanide (e.g.,potassium cyanide), and an acylating agent of either the formula RCOX or(RCO) O, wherein R is as hereinbefore defined, and X is a halide,prefierably chloride. The reaction is conducted in an aqueous mediumpreferably in the cold, and results in the preparation of the, twoisomers of the diesters of 2,S-dihydroxyhexanedinitrile. Compounds A,the acid moiety of the ester correspondingto the acylating agent used.

To prep are Compounds B, either of the isomers of Compound A is treatedwith hydrogen sulfide, the reaction preferably being conducted underbasic conditions. The reaction results in the preparation of CompoundsB, the diesters of 2,5-dihydroxydithiohexanediamide, wherein the acidmoiety of the ester corresponds to the acylating agent used in the firststep of the process.

Compounds B are then condensed with an ester oi halopyruvic acic of theformula: XCH COCOOR, wherein X is halo, preferably 'bromo, and-R is ashereinbefore defined. Thereaction is preferably conducted in an organicsolvent at an elevated temperature, such as the reflux temperature ofthe solvent, and results in the preparation of Compounds C, wherein Rand R'are as hereinbefore defined.

Compounds C are then hydrolyzed in the usual manner, as by treatmentwith a base, such as an alkali metal hydroxide (e.g., potassiumhydroxide) to yield Compound COOH 3 IV, 2,2(1,4-dihydroxytetramethylene)bis-(4-thiazocarboxylic acid).

Compound IV is then oxidized by treatment with sodium dichromate to giveCompound V, 2,2-succinylbis (4-thiazolecarboxylic acid) Compound V isthen treated with ammonium formate at an elevated temperature and theresulting formyl derivative hydrolyzed, as by treatment with a mineralacid to yield one of the final compounds of this invention, CompoundsVI, 2,2-( 1,4-dia11inotetramethylene) bis (4-thiazolecarboxylic acid)which can be converted to a salt in the usual manner by treatment withthe desired acid or base.

The following examples illustrate the processes of this invention (alltemperatures being in centigrade):

EXAMPLE 1 Benzoic Acid, Diesfer with 2,5-Dihydroxyhexanedinitrile (I) Amixture of 30 g. of succinaldehyde, 750 g. of cracked ice, 44 g. ofpotassium cyanide and 94 g. (78 ml.) of

andfinally with three portions of 250 m1. of water. The

chloroform extract is dried over anhydrous magnesium sulfate and afterremoving the latter and evaporating the solvent a residue of about 62 g.of heavy liquid remained.

' This residue on treatment with several volumes of hexane gives about19 g, of solid II.

Solids I and H are separately treated with ether, from which extractsbenzoic acid is recovered. The ether insoluble materials are treatedwith toluene on the steam bath and from these extracts a material, M.P.about 134136, separates.

A nalysis.Calcd for C H N O C, 68.96; H, 4.63; N, 8.04. Found: C, 68.89;H, 4.60; N, 7.93.

The toluene materials are then treated with dimethylformamide on thesteam bath and solution is complete. On cooling a crystalline productmelting at about 214- 216 separates.

Analysis.-Found: C, 68.96; H, 4.81; N, 8.10.

The infrared spectra of both compounds are substantially the same.

EXAMPLE 2 Benzoic Acid, Dieszer with 2,5-Dihydrxy- Dizhiohexanedz'amide(II) 7 Into a solution of 4.6 g. of the lower melting dinitrile obtainedin Example 1 in 25 ml. of dimethylformamide containing 0.3 ml. oftriethanolamine is bubbled hydrogen sulfied for six hours. After theaddition of gas, the stoppered mixture is allowed to stand for 24 hours.The mixture is then treated with hexane and enough ethanol to make themixture homogeneous. On standing a yellow solid slowly separates.Utimately with scratching and further diluting with hexane and ethanolabout g, of product is obtained. The prod-uct is crystallized from largevolumes of boiling ethanol and melts at about 203-205".

Analysis.-Calcd for C H N O S N, 6.73; S, 15.37.

Found: N, 6.94; S, 15.40.

, EXAMPLE 3 2,2'-(I,4 Dihydroxytetramethylene)bis(4 Thiazolecarboxylic)Acid Diezhyl Ester Diester With Benzoic Acid (111 A mixture of 2.5 g. ofthe dithioamide obtained in Ex: ample 2 and 2.5 g. of ethylbromopyruvate in 100 ml. of

ethanol is heated under reflux for one and one-half hours.

on the steam bath. On cooling a solid separates. The

4 4 solid is filtered oil to yield about 2.9 g. of solid, which iscrystallized from 100 ml. of boiling ethanol. The product melts at about144-145 Analysis.-Calcd for C3QH28N208S2: N, 4.60; S, 10.52. Found: N,4.68; S, 10.61.

EXAMPLE 4 2,2'- (1,4-Dihydroxytetramethylene) bis(4-Thiaz0lecarboxylz'cAcid) (IV) 2.1 g. of the ester obtained in Example 3 is suspended in 50ml. of absolute ethanol and 0.76 g. of potassium hydroxide in 5 ml. ofabsolute ethanol is added. White stirring at room temperature solutionoccurs within onehalf hour. The mixture is allowed to stand at roomtemperature overnight during which time a solid separates out. Theinsoluble material is filtered oii and washed with ethanol. It isdissolved in 10 ml. of water and the aqueous solution then Washed withether and then acidified with 1 N hydrochloric acid. From the acidsolution a precipitate slowly formed which is filtered off, washed withwater, and air dried to give about 1.0 g. of product, M.P. about235-240. From the original mother liquor on evaporation a residue ofabout 1.6 g. of product is obtained. The residue is dissolved in 101111.of water and after washing the aqueous solution with ether, the aqueoussolution is acidified with hydrochloric acid and the precipitate whichforms filtered ofif. This material is benzoic acid. From this and theprevious acid solution however, on cooling and standing about 0.2 g.additional product separates. Crystallized from boiling water, thiscompound separates out with one mole of water of crystallization whichis lost on drying at 130. The compound, 2,2- (1,4dihydroxytetramethylene)'bis( 4 thiazolecarboxylic acid) melts at about240-242 (dec.).

Analysis.Calcd for C H N O S C, 41.87; H, 3.51. Found: C, 42.01; H,3.95.

EXAMPLE 5 2,2'-Succinyl bis(4-Thiaz0lecarb0xylic Acid) (V) 600 mg. ofthe diol acid obtained in Example 4 is suspended in 15 ml, of glacialacetic acid distilled from chromium trioxide, and 500 mg. of sodiumdichromate in one-half a cubic centimeter of water is added to thesuspension. The whole is kept at 100 for 2 hours. On cooling aninsoluble material settles out. This material is filtered off and washedwith a large amount of Water and some dilute acetic acid. It weighsabout 400 mg. After crystallization from dimethylformamide the2,2'-s11ccinyl bis(4-thiazolecarboxylic acid) has a M.P. of about 284-286 (dec.).

Analysis.-Calcd for C H N O S C, 42.36; H, 2.37. Found: C, 42.52; H,2.90.

EXAMPLE 6 2,2 1 ,4-Diqminoretramthylene) bis( 4-T hiazolecarboxylicAcid) (VI) filtration. The filtrate is acidified with hydrochloric acidwhereupon a precipitate separates out. It is filtered OE and washed withwater to yield a mixture of -formyl derivatives. This mixture is heatedunder reflux .with 5 m1. of concentrated hydrochloric acid for an hour.Hydrolysis proceeds and the mixture becomes homogeneous. On evaporationthe residue obtained is dissolved in water from which VI slowlyseparates. It melts at about 235- 237 (dec.). CalCd for C12H14O4N4S2: C,H, N, 16.4; S, 18.7. Found: C, 42.5; H, 4.29; N, 16.4; S,

5 18.8. On Whatman No. 1 paper in a system of n-butanolacetic acid-water(4:1:1) the acid moves faster than cystine, RF 0.0080.10.

EXAMPLE 7 2,2'- (1 ,4-Diaminotetramethylene)bis(4-Thiaz0lecarboxylicAcid) Dihydrochloride 40 mg. of2,2'-(1,4-diaminotetramethy1ene)bis(4-thiazolecarboxylic acid) isdissolved in warm N-hydrochloric acid. The dihydrochloride salt whichforms slowly separates from solution and is removed by filtration.

EXAMPLE 8 2,2-(1,4-Diaminotetramethylene) bis(4-Thiaz0lecarboxylic Acid)Ammonium Salt 6 2,2'-(1,4-diaminotetramethylene)bis(4-thiazolecarboxylic acid) and saltsthereof.

2. 2,2 (1,4 diaminotetramethylene)bis(4 thiazolecarboxylic acid).

3. 2,2 (1,4 diaminotetramethylene)bis(4 thiazolecarboxylic acid)dihydrochloride.

4. A process for preparing2,2-(1,4-diaminotetramethylene)bis(4-thiazo1ecarboxylic acid) whichcomprises treating 2,2-succiny1 bis(4-thiazolecarboxylic acid) withammonium formate at an elevated temperature.

References Cited in the file of this patent UNITED STATES PATENTS2,725,382 Harman Nov. 29, 1955 2,760,933 Fields et a1 Aug. 28, 19562,836,564 Roberts et a1. May 27, 1958 DArnico July 1, 1958 OTHERREFERENCES 20 Beauvalet: Compt. Rend (Fr. Acad.), vol. 228, pagesElvidge et al.: Chem. Abstracts, vol. 47, col. 1058 (1933).

1. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF 2,2''-(1,4-DIAMINOTETRAMETHYLENE) BIS(4-THIAZOLECARBOXYLIC ACID) AND SALTSTHEREOF.